失叶率对小黑杨和兴安落叶松幼苗生物量和叶绿素含量的影响  

Effects of Defoliations on the Chlorophyll Contents and Biomass of the Poplar( Populus simonii × P. nigra) and Larix gmelinii Seedlings

作　　者：李媛媛[1] 张凯[1] 李霜雯[1] 严善春[1] 

机构地区：[1]东北林业大学林学院,哈尔滨150040

出　　处：《林业科学》2015年第3期93-101,共9页Scientia Silvae Sinicae

基　　金："十二五"农村领域国家科技计划课题(2011BAD37B01)

摘　　要：【目的】食叶害虫危害可造成树木失叶,影响树木的生物量及碳储量。研究虫害对杨树及落叶松幼苗生物量和叶绿素含量的影响,可为准确评估食叶害虫不同危害程度对杨树和落叶松碳汇能力的影响提供依据。【方法】选取小黑杨及兴安落叶松幼苗,模拟虫害进行剪叶25%,50%和75%处理,以不剪叶植物作为对照。在剪叶处理后第5,10,15,20天和25天取样,分别测定生物量和叶绿素含量的变化。【结果】生物量测定结果表明:各处理对2种幼苗的株高影响不显著(P>0.05),除落叶松失叶50%的根长显著大于对照(P<0.05)外,其他处理幼苗根长无显著变化。各处理的杨树根部鲜、干质量,全株生物量鲜、干质量均显著低于对照,茎鲜、干质量无显著变化。各处理的兴安落叶松根、茎的鲜、干质量及全株生物量鲜、干质量均显著低于对照。叶绿素测定结果表明:杨树叶片中叶绿素a含量高于叶绿素b,各处理组杨树的叶绿素含量均有不同程度的升高。失叶处理后第5天,处理组叶绿素含量比对照组增多,且失叶75%杨树植株叶绿素a和a+b的含量显著高于对照及失叶25%和50%(P<0.05);第10天,失叶率25%,75%处理组叶绿素b和a+b含量显著高于对照(P<0.05),各处理之间差异不显著;第15天,叶绿素含量各个处理组之间、及与对照差异均不显著(P>0.05);处理后20天,失叶50%的植株叶绿素a,b和a+b的含量显著低于对照和失叶25%(P<0.05),亦低于75%,但差异不显著;第25天,各处理叶绿素含量与对照间差异不显著(P>0.05),失叶50%显著高于失叶25%(P<0.05),亦高于失叶75%,但差异不显著。落叶松针叶中叶绿含量素b高于叶绿素a。落叶松叶绿素含量,在失叶量25%和75%处理组,有先升高后降低再升高的趋势,第5天叶绿素含量增加(P<0.05),第10天叶绿素含量降低(P<0.05),第15天与对照相比无差异,第20天叶绿素含量明显升高(P<0.05),到第25天叶绿素含量�Defoliations by leaf / needle- feeding insects can cause significant losses of tree growth,biomass,and carbon storage. Potential effects of artificial defoliations at 0%,25%,50% and 75% levels to mimic the defoliator damages on biomass and chlorophyll contents of the poplar（ Populus simonii × P. nigra） and larch（ Larix gmelinii） seedlings at 5,10,15,20 and 25 days after each treatment were investigated in the current study. Our results showed that there were no significant differences among the treatments in the plant height and root length（ P 〉0. 05） for both tree species,except that 50% larch seedling needle removal resulted in a significant increase of root length（ P〈0. 05）. Fresh and dryweights of the poplar seedling roots and whole seedling biomass in the three defoliation treatments were significantly lower than those of the untreated control,whereas the fresh and dry weights of the poplar seedling stems were not different among the treatments and the control. Fresh and dry weights of the larch seedling root,stem and whole seedling biomass in either defoliation group were significantly lower than those in the control group. Defoliations of poplar leaves resulted in different levels of increase in chlorophyll contents（ ＂a＂ 〉＂b＂）. Significant increase of chlorophyll contents already occurred at5 th day after the defoliation,with the 75% level being significantly higher than the control and the two lower levels（ 25%and 50%） for both chlorophyll ＂a＂and ＂a＂＋＂b＂（ P〈0. 05）. At 10 th day after the defoliation,chlorophyll ＂a＂and＂a＂＋＂b＂contents of 25% and 75% defoliations were significantly higher than that of the control,and were not different among the treatments. At 15 th days after the defoliation,there were no differences in chlorophyll contents among the treatments and the control（ P〉0. 05）. At 20 th day after the defoliation,chlorophyll ＂a＂,＂b＂and ＂a＂＋＂b＂contents of 50% defoliation were significantly lower than tho

关 键 词：兴安落叶松 小黑杨 失叶量 生物量 叶绿素 

分 类 号：S763.30[农业科学—森林保护学]